If it is Finnish, many of them had a .308 bore as compared to the .311 Russian rifles. So firing the .311 bullet through the .308 bore can cause some increased recoil.
Actually, it would more likely cause a gun-destroying kB!
The Soviet rifles were usually built with slightly oversize bores, probably to prevent catastrophic failures if fired with dirty ammo, but AFAIK all vintage ComBloc milsurp ammo is actually loaded with 0.308"-caliber bullets. You generally won't find any factory or milsurp ammo in 0.311" caliber; such ammo is usually handloaded by enthusiasts to increase accuracy of a rifle known to have an oversized bore.
Besides, nothing I see on this rifle indicates a Finnish barrel. They normally have a slightly different profile, don't have Soviet arsenal markings, and don't have Soviet sights on them.
But my question is this: I understand that these rifles are very cheap and abundant. Before i go refinishing or anything like that, does this rifle being Soviet or any of that make it something i should work on getting back to original standards, or just another rifle?
Frankly, it is Just Another Rifle. You can still mail-order unmolested M91/30s for $60-$120 depending on condition and markings, and the price for a garden-variety round-receiver WWII Izhevsk should fall at the low end of that range. (Of course, you'll have to add shipping costs, and transfer fees if you're not a C&R licensee.) For this price, IMHO it is not worthwhile to try to restore this rifle.
Also, for this price, neither is it worthwhile to repair the rifle if the action and/or trigger mechanism have been screwed up by the previous owner. I'd order a fresh M91/30 and chalk it up to experience.